/Engine/Source/Runtime/MessagingCommon/Public/MessageEndpoint.h
Sends a message to the specified list of recipients. Allows to specify message flags
template<typename MessageType> void Send ( MessageType * Message, EMessageFlags Flags, const [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [IMessageAttachment](API\Runtime\Messaging\IMessageAttachment), ESPMode::ThreadSafe > & Attachment, const [TArray](API\Runtime\Core\Containers\TArray)< [FMessageAddress](API\Runtime\Messaging\FMessageAddress) > & Recipients, const [FTimespan](API\Runtime\Core\Misc\FTimespan) & Delay, const [FDateTime](API\Runtime\Core\Misc\FDateTime) & Expiration )